/*
 * Copyright 2014 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrGLPrimitiveProcessor.h"

#include "builders/GrGLProgramBuilder.h"

SkMatrix GrGLPrimitiveProcessor::GetTransformMatrix(const SkMatrix& localMatrix,
                                                    const GrCoordTransform& coordTransform) {
    SkMatrix combined;
    // We only apply the localmatrix to localcoords
    if (kLocal_GrCoordSet == coordTransform.sourceCoords()) {
        combined.setConcat(coordTransform.getMatrix(), localMatrix);
    } else {
        combined = coordTransform.getMatrix();
    }
    if (coordTransform.reverseY()) {
        // combined.postScale(1,-1);
        // combined.postTranslate(0,1);
        combined.set(SkMatrix::kMSkewY,
            combined[SkMatrix::kMPersp0] - combined[SkMatrix::kMSkewY]);
        combined.set(SkMatrix::kMScaleY,
            combined[SkMatrix::kMPersp1] - combined[SkMatrix::kMScaleY]);
        combined.set(SkMatrix::kMTransY,
            combined[SkMatrix::kMPersp2] - combined[SkMatrix::kMTransY]);
    }
    return combined;
}

void
GrGLPrimitiveProcessor::setupColorPassThrough(GrGLGPBuilder* pb,
                                              GrGPInput inputType,
                                              const char* outputName,
                                              const GrGeometryProcessor::Attribute* colorAttr,
                                              UniformHandle* colorUniform) {
    GrGLFragmentBuilder* fs = pb->getFragmentShaderBuilder();
    if (kUniform_GrGPInput == inputType) {
        SkASSERT(colorUniform);
        const char* stagedLocalVarName;
        *colorUniform = pb->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                       kVec4f_GrSLType,
                                       kDefault_GrSLPrecision,
                                       "Color",
                                       &stagedLocalVarName);
        fs->codeAppendf("%s = %s;", outputName, stagedLocalVarName);
    } else if (kAttribute_GrGPInput == inputType) {
        SkASSERT(colorAttr);
        pb->addPassThroughAttribute(colorAttr, outputName);
    } else if (kAllOnes_GrGPInput == inputType) {
        fs->codeAppendf("%s = vec4(1);", outputName);
    }
}

void GrGLPrimitiveProcessor::addUniformViewMatrix(GrGLGPBuilder* pb) {
    fViewMatrixUniform = pb->addUniform(GrGLProgramBuilder::kVertex_Visibility,
                                        kMat33f_GrSLType, kDefault_GrSLPrecision,
                                        "uViewM",
                                        &fViewMatrixName);
}

void GrGLPrimitiveProcessor::setUniformViewMatrix(const GrGLProgramDataManager& pdman,
                                                  const SkMatrix& viewMatrix) {
    if (!viewMatrix.isIdentity() && !fViewMatrix.cheapEqualTo(viewMatrix)) {
        SkASSERT(fViewMatrixUniform.isValid());
        fViewMatrix = viewMatrix;

        GrGLfloat viewMatrix[3 * 3];
        GrGLGetMatrix<3>(viewMatrix, fViewMatrix);
        pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
    }
}